01M transmission problems solved

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
I just performed some surgery on my 01M today, and it appears to have fixed the shifting problems. I'll continue to post as I put miles on it, or if the problems resurface. For now, here is what I did:

~ purchased car at 116,000
~ noticed the common 01M failures around 130,000 which were false neutral in first when I came to a stop, hard 2-3 and 3-4 shifting, inconsistant shifts, occasional hunting during shifting, and the occasional thunk that felt like something had actually broken
~ I changed the filter and performed a line pressure boost of about 16psi at 135,000 with marginal improvement
~ I filled the tranny fluid higher per a post I found, and found minimal improvement
~ winter set in, and lower temps seemed to help the shifting since the tranny stayed cooler, but as soon as it warmed up enough, the problems were back
~ In the last few days, hard shifting just started appearing that made me think hard parts were breaking off my gears
~ I had purchased a re-man valve body off eBay with the Sonnex mods, and installed it today
~ Shifting is now silky smooth, no false neutrals showed up, even after the car warmed up, the shifts feel much more positive and consistant, and it doesn't feel like the transmission is taking forever to engage the next gear like it had before.

My conclusions to date:
~ the re-man valve body definitey fixed the problems... for now
~ cooler temps help the transmission operate better
~ the reason the tranny operates well when cool, and badly when warm/hot may come from worn out seals allowing the tranny fluid to leak past more easily when it is hotter and thinner
~ a clean tranny filter does seem to improve shifting performance
~ overfilling the tranny didn't really help anything on my tranny

Future work:
~ observe the tranny operation with the new valve body for at least 5,000 miles
~ install a tranny fluid cooler come spring time if the transmission is still operating



The biggest thing 01M owners must keep in mind is that parts break for a reason. I am sure there are many failure modes for these transmissions, but I can almost guarantee you that if your transmission is shifting harshly, or thunking into first gear, then you are putting undue stress on it that will cause it to fail. So, before your transmissions fail, try doing something to fix it.

To whoever is planning on how to respond to this post with a statement about how these trannys are crap and will always fail and there is no use to try to work on them since it is a waster of time:
~ Have you ever actually determined why they fail?
~ Have you ever tried to find a solution to the failure before it occurs?
~ Do you have any insight to offer on the exact failure mechanisms that occur so that we can find out how to remedy the failure modes before they cause a failure?
~ Why do the re-man VW units behave and last better than the original ones? Is it possibly because they utilize some modifications including the Sonnex mod that was done to my new valve body?


I bought my valve body off eBay. This is the direct line to the business I bought it from. Central Valve Bodies. 1-877-341-0266

Camelman
 

pruzink

Veteran Member
Joined
Sep 25, 2004
Location
Granbury, Texas
TDI
GLS, 2004, silver
Nice post, thanks for the info. I have an 04 TDI Jetta with the 09A, but my daughter has an 01 Jetta with the 01M so I usually read up on anything concerning either. How much did you pay for the replacement valve body? Was it pretty straight forward to replace (disconect the solenoids, unbolt & install new valve body)? Do you know if all of the solenoids and the harness get replaced on the remanufactured valve bodies (I think there are about 3 Sonnax mods with oversized valve bodies that are sold for this transmission)?
I would say that as soon as an 01M starts acting up (harsh shifting, inconsistent shifting), that the 1st thing you want to do is drop the pan and look for evidence of gear or clutch failure (metal chunks or shavings, clutch friction material in the oil). If you don't find any of that I would say that it well worth the risk that doing what you did will correct your problem. There have been a lot of good posts in here by "oilhammer" who has a lot of experience working on these, he said that the VW remanufactured transmissions are rebuilt to a higher standard than most other ones sold (the down side is that they are quite expensive, 4-5K installed). I have seen these valve bodies being sold on Ebay at a reasonable cost, I think that the dealers get 1K for a replacement valve body.
 

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
I bought my valve body for ~$330. The install was very straight forward, and new solenoids are included.
There were only two sticky points I ran across. The old solenoids would not let go of the wiring harness clips, so I just snipped the solenoid plugs with some wire snips to unhook the wiring harness.
The second thing was the shift linkage. I would recommend taking it off both the valve body and the shift linkage assy, then install the new valve body, then reattach the shift linkage. The shift linkage assembly has a flexible retainer that can be bent out of the way for removal and install, then bent back in place afterwards. You'll see what I mean if you dig around in there.
I reused the old wiring harness.

I did find a few small pieces of metal in my transmission pan when I changed the fluid a while back, but nothing that looked any worse than other trannys I've pulled apart. It doesn't seem to be causing a problem now though, and there were no new pieces in there when I changed the valve body today. We'll see how it goes.

Be careful of one of some of the guys on eBay. From what I found, there were a few selling valve bodys with new soleniods for ~$100. However, they raised their rates when the saw the guys who were actually rebuilding the valve bodys and performing the Sonnex mods for ~$350. So, do your research before you buy. The business I listed in my first post seemed to be reliable.

Let me know if you decide to do this. I'd be interested in how it goes.

By the way, is it better to do this before the tranny starts acting up, or afterwards? Just something to think about.

Camelman
 

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
The old valve body is going back as a core. I'd rather not pull it apart. I'll dig around in it before I send it back to see if there is anything noticably wrong with it though.
 

Left Coast Resident

Ubẽr Clubbie
Joined
Apr 23, 2006
Location
San Fernando Valley (Los Angeles)
TDI
2001, 2002 & 2003 Jettas
I talked to my trans guy earlier this year (doesn't specialize in VW's, but says he's rebuilt a couple of dozen 01M's in the last 5 years) and he told me that hairline cracks in the the valve body that are almost impossible to see, but leak fluid under operating pressure, are a problem. For this reason he says you've got to be really careful if you are installing a rebuilt one (or rebuilding it yourself).

What Sonnax mods were done to the valve body?

Al
 

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
I'm not sure which mods were done. Best off calling the vendor I purchased it from.

I now have 1000 miles since install, and the shift points are settling in. The shifts are more firm and positive than they had been before. There is still no false neutral in first, and I haven't felt any of the scary shifts that had me worried things were breaking.
 

1sparrow

Active member
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Oct 30, 2003
Location
Latrobe Pa.
TDI
00 jetta tdi auto black / 00 jetta tdi 5spd blue
Camelman
This is very good news to those of us with over 100,000 on the 01M. Thanks so much for the post.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Wow, that's a good n00b! 5 gold stars! ;)

Seriously though, excellent post. I hope this solves the problems for you and increases the life of your 01M.
 

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
I haven't put a lot of time into picking a tranny cooler yet. I'm going to wait until it warms up before I do that. Just can't spare the cash right now.

I've been thinking about timing of installing a new valve body. I have received some PMs from people planning on doing something like this when their trannys start to act up. However, I think it would be better done as a preventative measure rather than a reactive measure. Once these things start acting up damage has either been done, or is being done. It seems to me that it would be better to just stop the damage from occuring at all by doing the mod sooner. Anyone else have any thoughts on it?
 

PharoahTDI

Veteran Member
Joined
Apr 7, 2004
Location
Alliston, ON
TDI
None
Well let me know about the cooler. I did notice mine is running much better in the cold too. My plan is to replace the valve body, fluid and filter and add a cooler in the spring.

Also, did the person on ebay want the core back?
 

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
PharoahTDI,

I think we are on track to do the same mods. I'll post up here when I figure out which cooler I'm going with. Let me know if you find a good one too.

The guy from eBay needs the old valve body back as a core. I bought mine from a guy with the eBay handle "donnylester". I'd recommend him.
 

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
PharoahTDI, thanks for the post.

Everyone, please feel free to add useful information to this thread. I'm sure we will continue to see plenty of failures on these trannys, but at least it looks like we have some options on making them last a little longer.

I found an interesting write-up on these trannys with some good info on points of failure. Warning though, the hard parts cost to remedy some of these failures may not be worth it in the long run. The information is still pretty interesting though.
This guy also lists a reason for the poor shifting when warm. This just adds credence to the concept of installing a good tranny cooler when your tranny starts to act up to buy you some more life.

http://forums.fourtitude.com/zerothread?id=3465582

By the way, I can't find a decent post on how to reset the fuzzy logic on these trannys. Can someone post it? I'm interested in both the standard reset, and the "sport" reset. Preferably without the use of Vag-Com.

Camelman
 

aNUT

Vendor , w/Business number
Joined
Nov 29, 2006
Location
Boulder, Colorado
TDI
'01 TT (ALH-ish), B7 Audi gasser, '05 Golf
That's good information. Thanks.

With regard to the trans cooler: There is already a transmission cooler that interfaces with engine coolant. An additional cooler (and lower fluid temperatures) may help the 01M last, but I suspect that unless the new cooler is stand alone, and the OEM cooler is removed, you may be fighting the cooling system components that are trying to keep coolant temp relatively constant.
 

QSK

Member
Joined
Dec 26, 2007
Location
Minot, North Dakota
TDI
2000 Jetta
Does anyone know where I could get an explanation of powerflow or exploded view of an 01M? I have looked through the transmission section in my Bently manual. There appears to be no technical information on the internal workings of the transmission.
 

camelman

Veteran Member
Joined
Oct 25, 2007
Location
San Francisco, CA
TDI
2002 Jetta Auto
QSK, I don't have any info on that.

3000 mile update:
The tranny is still working fine. The hard 2-3 shift is back when the tranny is warmed up, but it is much better than it was before the valve body swap. All other gear changes are normal, and the first gear false neutral is gone.
The valve body swap certainly seems to have cleared up the first gear false neutral, and to have somewhat mitigated the harsh shifts.

Camelman
 

MOGolf

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camelman said:
By the way, I can't find a decent post on how to reset the fuzzy logic on these trannys. Can someone post it? I'm interested in both the standard reset, and the "sport" reset. Preferably without the use of Vag-Com.

Camelman
The only reset available without VAG-COM is to turn the key to 'on' but do not start the car. Next press the go pedal to the floor for at least 3 seconds. Release the pedal. Turn the key off.

This has reset the 'fuzzy logic'. It starts off with 'sport' mode settings and adapts to lesser depending on your driving.

Using VAG-COM you can change the module coding from the adaptive setting (00000) to 'economy mode' (00011) or 'sport mode' (00012). For best results, use VAG-COM to access 'basic settings' in the TCM, read '000' group, then exit the controller.

For the harsh shifting, I recommend making sure the multi-wire connector on top of the transmission is fully seated. You might disconnect and reconnect it. Also check the transmission fluid level. This will require the use of tool that can access the transmssion fluid temperature reading in the TCM. With the car idling, fluid should just begin to drip out of the drain hole when the reading reaches about 30 C. If overfilled let it drain out until just dripping at that temperature.
 
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dhollist

Active member
Joined
Aug 27, 2003
Location
Ann Arbor, MI
TDI
2001 Jetta GLS
Correction to fill procedure

This should read "drain hole" not "fill hole". There is a red plastic sleeve inside the drain hole that sets the proper height of oil in the pan. It is essential that the car is parked on a level surface and the temperature is correct as indicated below.

So the corrected sentence is:
"With the car idling, fluid should just begin to drip out of the drain hole when the reading reaches about 30 C."

Dave

MOGolf said:
The only reset available without VAG-COM is to turn the key to 'on' but do not start the car. Next press the go pedal to the floor for at least 3 seconds. Release the pedal. Turn the key off.

This has reset the 'fuzzy logic'. It starts off with 'sport' mode settings and adapts to lesser depending on your driving.

Using VAG-COM you can change the module coding from the adaptive setting (00000) to 'economy mode' (00011) or 'sport mode' (00012). For best results, use VAG-COM to access 'basic settings' in the TCM, read '000' group, then exit the controller.

For the harsh shifting, I recommend making sure the multi-wire connector on top of the transmission is fully seated. You might disconnect and reconnect it. Also check the transmission fluid level. This will require the use of tool that can access the transmssion fluid temperature reading in the TCM. With the car idling, fluid should just begin to drip out of the fill hole when the reading reaches about 30 C. If overfilled let it drain out until just dripping at that temperature.
 

dhollist

Active member
Joined
Aug 27, 2003
Location
Ann Arbor, MI
TDI
2001 Jetta GLS
Low Line Pressure and/or Soft Shifts

ATRA Technical Bulletin #623 (Google it) may be helpful for those experiencing soft shifts. Apparently the manual valve inside the transmission can become misadjusted (hence the reference to using threadlocker after correctly adjusting it)

 
Last edited:

MOGolf

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Jun 27, 2001
Location
underneath something
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2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
Yes, drain hole. Fixed the post. Brain needed a fluid check. ;) It slipped.
 

dhollist

Active member
Joined
Aug 27, 2003
Location
Ann Arbor, MI
TDI
2001 Jetta GLS
New valve body breathes new life into near-dead 01M

At Camelman's suggestion I bought a remanufactured valve body from Central Valve Bodies (website or eBay) and installed it last weekend. The problem with our 01M transmission was that it would barely move the car in reverse. Once warm, we would have to rev the engine to ~2000 rpm to get any sort of reverse gear engagement, and even then there was a lot of slippage so the car would barely move. Even before the reverse problem, this transmission always felt "sloppy" with delayed engagements, false neutrals between 2-3 and 3-4, etc. A lot of online research led me to believe that it was worth trying a valve body swap before committing to a new transmission. Camelman's positive experience with a reconditioned valve body from Central Valve Bodies was instrumental in my decision to give this a try. Donny from CVB is awesome, and gave me several tips about setting the manual valve correctly when installing the new valve body.

I also replaced the ATF, filter, and pan gasket with genuine VW parts and fluid. I can't imagine reusing any of those things or using cheapo stuff from the local parts store when any kind of problem means a $5000 transmission goes bang. After adding 3 liters of ATF, I performed a restored basic settings (key on, accelerator pedal hard to the floor for 5 seconds, release accelerator, key off), started the engine, slowly cycled the transmission through all of the shifter positions, then let the engine idle with the trans. in park until the temp came up to 35deg. C as shown in VAG-COM block 005. Then I removed the drain plug (which I had left finger tight per drivbiwire's excellent ATF change instructions) and added ATF until it started running out the drain hole. Once it stopped running out, I installed and tightened the drain plug. Be sure to use a good torque wrench for the drain plug and trans. pan bolt torques because they strip easily.

Finally, time to take it for a test drive! I was encouraged initially, because reverse gear engaged pretty quickly and actually made the car move. Remember, before surgery the car would barely move in reverse without revving the engine. But now the already warm transmission was actually moving the car just off idle. WOOHOO! So down the road I went, with firm forward gear engagements. I got nervous a few times as the 2-3 shifts sometimes didn't seem 100% right, with a slight false neutral and the engine revving between gears. I gritted my teeth and hopped on the expressway, hoping that a little bid of driving at various speeds would help the adaptive shift strategy to 'figure things out'. Sure enough, after 10 or so miles of highway speed driving with the occasional (driver induced, pedal to the floor) kickdown, I got off the highway and did some stop-and-go driving, and the 2-3 shift problem had gone away. I also still had reverse with ATF temps in the 85-90deg. C region.

So far we've probably put 300-500 miles on it, and other than the first 5-10 miles, the shifting has been firmer/crisper/quicker than we ever experienced in this car or any other VW with an 01M transmission. I'd highly recommend a valve body, ATF, and filter change before throwing in the towel and installing a new transmission or doing a auto->manual conversion. Just my 2 cents.

Thanks for the great tip Camelman! And thanks for the additional information you sent me Chinaloy! Finally, thank you Drivbiwire for the excellent how-to on changing the ATF!

Dave


camelman said:
I bought my valve body for ~$330. The install was very straight forward, and new solenoids are included.
There were only two sticky points I ran across. The old solenoids would not let go of the wiring harness clips, so I just snipped the solenoid plugs with some wire snips to unhook the wiring harness.
The second thing was the shift linkage. I would recommend taking it off both the valve body and the shift linkage assy, then install the new valve body, then reattach the shift linkage. The shift linkage assembly has a flexible retainer that can be bent out of the way for removal and install, then bent back in place afterwards. You'll see what I mean if you dig around in there.
I reused the old wiring harness.

I did find a few small pieces of metal in my transmission pan when I changed the fluid a while back, but nothing that looked any worse than other trannys I've pulled apart. It doesn't seem to be causing a problem now though, and there were no new pieces in there when I changed the valve body today. We'll see how it goes.

Be careful of one of some of the guys on eBay. From what I found, there were a few selling valve bodys with new soleniods for ~$100. However, they raised their rates when the saw the guys who were actually rebuilding the valve bodys and performing the Sonnex mods for ~$350. So, do your research before you buy. The business I listed in my first post seemed to be reliable.

Let me know if you decide to do this. I'd be interested in how it goes.

By the way, is it better to do this before the tranny starts acting up, or afterwards? Just something to think about.

Camelman
 

Plutogogo

Well-known member
Joined
Oct 26, 2000
Location
Atlanta, GA USA
Hardness connector

Does anyone know where I can purchase connector for the hardness wire?
there are 7 connectors from the hardness cable to the solenoids.
 

dhollist

Active member
Joined
Aug 27, 2003
Location
Ann Arbor, MI
TDI
2001 Jetta GLS
Awaiting final verdict

camelman said:
dhollist,

Awesome! I'm glad it worked out for you. Please post every couple thousand miles on how it is doing.

Camelman
Well, it would appear that the fix was short lived. The problem with reverse engagement came back, so the car is at the local dealer for repair since we can't continue without reliable transportation. I'll post again after we get the prognosis from the dealer.
Dave
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
dhollist said:
Well, it would appear that the fix was short lived. The problem with reverse engagement came back, so the car is at the local dealer for repair since we can't continue without reliable transportation. I'll post again after we get the prognosis from the dealer.
Dave
I have long since lost count how many times I have seen this same scenario play out. Sorry it did not 'stay fixed' but they rarely do. :eek:
 

Matt-98AHU

Loose Nut Behind the Wheel Vendor
Joined
Apr 23, 2006
Location
Gresham, OR
TDI
2001 Golf TDI, 2005 Passat wagon, 2004 Touareg V10.
dhollist said:
Well, it would appear that the fix was short lived. The problem with reverse engagement came back, so the car is at the local dealer for repair since we can't continue without reliable transportation. I'll post again after we get the prognosis from the dealer.
Dave
Good ol Howard Cooper I'm assuming? ;)
 
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